Joint signaling method for motion vector differences

Abstract

The present disclosure relates to encoding and decoding motion vector differentials for inter predicting video blocks, the method including: receiving a coded video bitstream; retrieving from the coded video bitstream a flag indicating whether an inter prediction mode is a JOINT_NEWMV mode for a current block of a current frame, the JOINT_NEWMV mode indicating that a first delta motion vector (MV) for a first reference frame from reference list 0 and a second delta MV for a second reference frame from reference list 1 are jointly signaled; in response to the flag indicating that the inter prediction mode is a JOINT_NEWMV mode, retrieving a joint delta motion vector (MV) for the current block; deriving a first delta MV and a second delta MV based on the joint delta MV; and decoding the current block based on the first delta MV and the second delta MV.

Claims

1. A method for decoding an interpreted video block: A device including a memory for storing instructions and a processor for communicating with the memory receives a coded video bitstream; Steps include: the device extracting a flag from the coded video bitstream indicating whether the interprediction mode is JOINT_NEWMV mode with respect to the current block of the current frame, wherein JOINT_NEWMV mode indicates that a first delta motion vector (MV) for a first reference frame from reference list 0 and a second delta MV for a second reference frame from reference list 1 are signaled together; In response to the flag indicating that the interpretation mode is JOINT_NEWMV mode: The device extracts the joint delta MV for the current block from the coded video bitstream; and The device derives the first delta MV and the second delta MV based on the joint delta MV; and The device decodes the current block of the current frame based on the first delta MV and the second delta MV; A method comprising the following, wherein the JOINT_NEWMV mode is signaled together with at least one of the NEAR_NEARMV mode, NEAR_NEWMV mode, NEW_NEARMV mode, NEW_NEWMV mode, and GLOBAL_GLOBALMV mode.

2. In the method according to claim 1: The mode is one of the composite reference modes; and The syntax elements extracted from the coded video bitstream represent the interprediction mode, in a method.

3. In the method according to claim 1: Whether the aforementioned interpretation mode is JOINT_NEWMV mode is: The first picture order count (POC) distance between the first reference frame and the current frame, The second POC distance between the second reference frame and the current frame, or A method based on at least one of the directional relationships between the first reference frame and the second reference frame with respect to the current frame.

4. In the method according to claim 3: A method wherein the interpretation mode is the JOINT_NEWMV mode, depending on whether the directional relationship indicates opposite directions or whether the first POC distance is equal to the second POC distance.

5. In the method according to claim 3: A method wherein, depending on the directional relationship indicating opposite directions and the first POC distance being equal to the second POC distance, the interpretation mode is the JOINT_NEWMV mode.

6. A method for decoding an interpreted video block, the method being: A device including a memory for storing instructions and a processor for communicating with the memory receives a coded video bitstream; Steps include: the device extracting a flag from the coded video bitstream indicating whether the interprediction mode is JOINT_NEWMV mode with respect to the current block of the current frame, wherein JOINT_NEWMV mode indicates that a first delta motion vector (MV) for a first reference frame from reference list 0 and a second delta MV for a second reference frame from reference list 1 are signaled together; In response to the flag indicating that the interpretation mode is JOINT_NEWMV mode: The device extracts the joint delta MV for the current block from the coded video bitstream; and The device derives the first delta MV and the second delta MV based on the joint delta MV; and The device decodes the current block of the current frame based on the first delta MV and the second delta MV; The method further includes: The device provides the context for deriving the interprediction mode: The first picture order count (POC) distance between the first reference frame and the current frame, The second POC distance between the second reference frame and the current frame, or A method comprising the step of deriving based on at least one of the directional relationships of the first reference frame and the second reference frame with respect to the current frame.

7. The method according to claim 1, further: A method comprising the step of the device performing optical flow motion refinement for the current block, depending on whether the interpretation mode is the JOINT_NEWMV mode.

8. A method for decoding an interpreted video block, the method being: A device including a memory for storing instructions and a processor for communicating with the memory receives a coded video bitstream; Steps include: the device extracting a flag from the coded video bitstream indicating whether the interprediction mode is JOINT_NEWMV mode with respect to the current block of the current frame, wherein JOINT_NEWMV mode indicates that a first delta motion vector (MV) for a first reference frame from reference list 0 and a second delta MV for a second reference frame from reference list 1 are signaled together; In response to the flag indicating that the interpretation mode is JOINT_NEWMV mode: The device extracts the joint delta MV for the current block from the coded video bitstream; and The device derives the first delta MV and the second delta MV based on the joint delta MV; and The device decodes the current block of the current frame based on the first delta MV and the second delta MV; The method further includes: The steps include: the device extracting a flag from the coded video bitstream indicating whether optical flow motion refinement is performed for the JOINT_NEWMV mode; and Depending on whether the flag indicates that the optical flow motion refinement is performed for the JOINT_NEWMV mode, the device performs the optical flow motion refinement for the current block; A method that includes this.

9. The method according to claim 1, further: The device retrieves a flag from the coded video bitstream indicating whether the JOINT_NEWMV mode is applicable to the current block; A method that includes this.

10. In the method according to claim 8: A method in which the aforementioned flag is signaled in a high-level syntax element that includes at least one of the following: a sequence parameter set (SPS), a video parameter set (VPS), a picture parameter set (PPS), a picture header, a tile header, a slice header, a frame header, a coding tree unit (CTU) header, or a superblock header.

11. A device for decoding interpreted video blocks: Memory for storing instructions; and A processor that communicates with the aforementioned memory; An apparatus comprising, wherein when the processor executes the instruction, the processor is configured to cause the apparatus to perform the method according to any one of claims 1 to 10.

12. A non-temporary, computer-readable storage medium for storing instructions, wherein, when an instruction is executed by a processor, the instruction is configured to cause the processor to execute the method according to any one of claims 1 to 10.

13. A computer program that causes a processor to perform the procedure described in any one of claims 1 to 10.

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